Henry Edgar Hall. 28 September 1928—4 December 2015

Henry Edgar Hall was a leading experimental and theoretical low temperature physicist of his generation, who, working first in Cambridge and then in Manchester, made important contributions to our knowledge and understanding of superfluidity in both liquid4 He and liquid3 He. His work focused significantly, but not exclusively, on the role of topological defects, such as quantized vortex filaments, in superfluid behaviour. He also contributed in important ways to the development of the3 He–4 He dilution refrigerator, which has since played a vital role in experimental work requiring temperatures below 1 K.